There is no way to know whether Rep. Eric Cantor's support of immigration legislation directly led to his defeat in the Virginia Republican primaries Tuesday night. But judging from the reaction Wednesday to that loss, it's getting a lot easier to declare that Congress isn't going to pass an immigration bill.

Nearly two-thirds of voters in Cantor's primary (72%) expressed support for an immigration bill similar to the one passed by the Senate last June that would allow most of the nation's 12 million undocumented immigrants eventually to become U.S. citizens, according to a poll by the liberal Public Policy Polling firm.

Despite the claims of Cantor's opponent, Dave Brat, that Cantor was a full-throated supporter of "amnesty" for undocumented immigrants, Cantor never filed an immigration bill, and the House of Representatives had done nothing on the issue since it passed a handful of smaller bills through committee 12 months ago.

"Every time I talked to Republican members, business leaders, growers and faith leaders about immigration reform in the last several months, I consistently heard that the House leadership wanted to move forward, but they did not have Cantor's support," Sen. Charles Schumer, D-N.Y., said on the Senate floor Wednesday. "Cantor was the choke point for immigration reform for these past few months."

Whatever ultimately led to his defeat, even the most ardent immigration activists struggled to refute the idea that Cantor's loss makes it nearly impossible to squeeze an immigration bill through the Republican-led chamber.

"It makes it tougher, there's no denying that," said Ali Noorani, executive director of the National Immigration Forum, a group that helped corral the support of conservative business, law enforcement and religious leaders to help sway Republicans in Congress.

Eliseo Medina, the chairman of the immigration campaign for the Service Employees International Union, who went on a 22-day hunger strike last year to push for an immigration bill, said many Republicans who were possible "yes" votes on an immigration bill are running away from the issue.

"Unfortunately, the House has never been a profile-in-courage institution, so any little bump or burp scares them to death," he said.

Frank Sharry, the executive director of America's Voice who has been fighting for an immigration overhaul since he came to Washington in 1990, said Cantor's loss blows up a last-minute attempt by Republicans to organize support for an immigration bill.

"All of the game-planning, as I understood, was, 'After Cantor's primary win, we'll sit down with leadership and discuss how to move forward,' " he said. "This definitely kicks that leg out of the stool."

Even the timing is damaged by Tuesday's results. Cantor announced that he will step down as majority leader at the end of July. Clarissa Martinez of the National Council of La Raza, the country's largest Hispanic advocacy organization, said the days spent reorganizing Republican leadership will cut into the already-dwindling window to get a bill through the House.

"That takes away some days, and the calendar between now and the August recess is short," she said.

Supporters of immigration changes tried to point to the few remaining reasons for optimism.

Republican Sen. Lindsey Graham, one of the co-sponsors of the Senate's immigration bill who pushed for the House to follow that lead, won an easy primary victory in conservative South Carolina. Republican Rep. Renee Ellmers won in the North Carolina Republican primary in March after she openly supported legalizing the nation's undocumented immigrants. Cantor's race featured fewer than 70,000 people, far from a national referendum on immigration.

Hope also remains in a rather unlikely place: Speaker John Boehner, R-Ohio.

The speaker rejected the Senate's immigration bill soon after it was passed, saying the House would not even consider it. But he called immigration legislation a "priority" for his chamber. In January, he released a set of principles that would guide House efforts to pass an immigration bill and has encouraged members to press the issue among Republicans.

Rep. Jeff Denham, R-Calif., one of the Republicans who has supported an immigration bill, said, "Immigration reform is not dead. Congress should remain focused on fixing problems, including immigration reform, regardless of the results of a primary election in Northern Virginia."

That won't be easy. "It'll take Boehner putting his career on the line to give us a shot," Sharry said. "It is possible? Yes. Is it likely? No."